What was found
DISCREPANCY - DURING TAKEOFF ROLL (SEQU), BEFORE 80 KNOTS, REVERSE NR 3 UNLOCK ILLUMINATE. AFTER TROUBLESHOOTING, ACCOMPLISHED REVERSE LOCKOUT NR 3 ENGINE IAW 78-32-00 / TRANSFER TO DMI 6057, CAT "C", PLACARAD INSTALLED IAW MEL 78-30-1.